Visible light active metal-free photocatalysis: N-doped graphene covalently grafted with g-C3N4 for highly robust degradation of methyl orange

Green and sustainable metal-free heterogeneous photocatalyst and their structures are an essential role for the environmental remediation and clean energy production, but the construction of meal-free, highly active and low-cost photocatalyst has remained a great challenge. This paper deals with a simple and novel metal-free nitrogen-doped graphene covalently grafted with graphitic carbon nitride (NG@g-C3N4) nanocomposite was synthesized by an ultra-sonication method. The as-prepared nanocomposite was characterized by UV–vis diffuse reflection spectroscopy, FT-IR, XRD, TEM, BET surface areas, photoluminescence and electrochemical impedance spectroscopy. Notably, the NG@g-C3N4 is exhibits efficient degradation of methyl orange and the efficiency was achieved by nearly 100% within 35 min. These remarkably observed photocatalytic activities can be attributed to the well adsorption capability of visible light, high surface area and great charge separations are due to the synergistic effect of NG grafted to g-C3N4. Meanwhile, the photocatalytic mechanism is also studied and investigated. It is hoped that our work can provide a robust way to create metal-free photocatalysts for water remediation and beyond.